KR20020053079A - Device for cutting slits in plastic tubes - Google Patents

Abstract

The apparatus for forming a slit in a plastic tube forms a number of cuts through which the tubing passes and spaced around the tubing. The device comprises a plurality of rotatable members 3 arranged at different circumferential positions around the passing tube passage 2. Each rotatable member is provided with a tube cutter 25 which is directed to the tube passage 2 at a rotation of each member 3 and spaced apart from the tube passage. This rotatable member 3 is adjustable in the radial direction of the tube passage 2 to accommodate the change in diameter of the tubing.

Description

Device for cutting slits in plastic tubes {DEVICE FOR CUTTING SLITS IN PLASTIC TUBES}

In certain uses of plastic pipes, there is a need for the pipes to be perforated. In one example only, the embedded profiled drain pipe is provided with small cuts or slits spaced apart from each other around the trough of the profiled pipe.

Conventionally, different devices have been used or proposed for perforated members such as pipes. U.S. Patent Nos. 4,180,357 and 4,218,164 issued to Gerd Lupke describe the use of a plurality of threaded cutters rotatably mounted around a central bore through which tubing passes for drilling by threaded members. A tube drilling apparatus in form is disclosed. The device in these two patents is very efficient during operation, but the device is not easily adjusted for different tube diameters.

U.S. Patent Nos. 5,381,711 and 5,385,073 to Truemner et al. Disclose tube punchers, which are driver cutter wheels supported for drive shafts at different locations around the drill. Has According to the two patents, the drive axes have an angle, ie the drive axes are not parallel to the axis of the tube passing through the perforator. The bending of the drive axis results in the inclination of the cutter wheel which, in accordance with each patent, keeps the wheel in the trough of the tube to accommodate very fine fluctuations of the tubing. In addition, each of these patents allows the driver cutter wheel to be exchanged with other driver cutter wheels to accommodate more significant changes in tubing, for example tubing of different diameters.

The present invention relates to a tube cutting device for perforating tubing, such as profiled drainage tubing.

1 is a cross-sectional view of a tube cutting device according to an embodiment of the present invention,

FIG. 2 is an enlarged cross sectional view of one of the individual tube cutting stations from the apparatus of FIG. 1;

3 is a cross-sectional view of a tube cutting device according to another preferred embodiment of the present invention.

The present invention provides a tube cutting device that can very quickly and easily adjust the change in the passing tubing, the change being caused by a coupling section formed in the tubing that should not occur or be cut as a result of the different sizes of tubing. coupling sections), for example, as a result of different tube sections.

In particular, the tube cutting device of the present invention, through which the tube passes and forms a plurality of cuts or slits around the tube, comprises a plurality of rotatable members through which the tube passes and disposed at different peripheral positions around the tube. Each rotatable member is provided with a tube passage and a tube cutter facing away from the tube passage with the rotation of each member.

According to the invention, the rotatable member is adjustable in the radial direction of the tube passageway to accommodate the change in diameter in the tubing passing through the device.

A plurality of tube cutters and in some cases all rotatable tube cutter members in accordance with an aspect of the present invention are responsive to a single controller that provides simultaneous uniform radial direction adjustment of all members.

The above as well as other advantages will be described in more detail according to preferred embodiments of the present invention.

1 shows a cutting device, generally designated 1 for cutting tubing, and a profiled plastic tubing through the device. The tube cutting device comprises a plurality of individual cutting stations 3 through which a central tube passage or bore 2 penetrates and is circumferentially spaced around the central tube passage or bore.

Each of the tube cutting stations 3 is shown in more detail in FIG. 2 and will be described in detail below.

Referring to Fig. 1, a feature of the present invention lies in the radial direction tunability of each cutting station 3. In the particular example shown, this adjustability is provided through a mechanical linkage system that includes a plurality of levers that are pivotally connected to one another.

More specifically, the interlock system comprises a main or master lever 5, through which a single movement of the lever allows a plurality of slave levers to allow each cutting station to make uniform radial adjustments simultaneously. (saver lever) This slave lever comprises a slave lever 6 pivotally connected to the inner end of the master or main lever 5 and a number of additional slave levers 7 outwardly around the device. As shown in FIG. 1, these two slave levers are pivotally connected to the center of the master lever 5.

An additional slave lever 9 is pivotally connected to the end of the lever 7, which then pivots to a slave lever 11 which rotatably supports each cutting station 3. Connected. One minimal difference in the overall arrangement is that the slave lever 6 which is pivotally connected to the inner end of the master lever 5 as described above is used to support the cutting station 3a. The actual shape of the cutting station 3a is the same as the cutting station 3.

The master lever 5 is pivotally connected to the reciprocating plunger 13 at the outer end.

Movement of the plunger in one direction, ie extending outwardly of the plunger, in turn generates movement of all the slave levers to pull each cutting station outward from the position shown in FIG. The degree of extension of the plunger indicates the degree of motion of the cutting station. For example, the plunger may extend far enough to pull the cutting station completely away from the central bore 2 such that something as large as the engaging section of the tube passes through the apparatus without contacting the cutting station. The cutter can also be pulled out to cut larger diameter tubing.

For example, if it is desirable to pull each cutting station radially inward from the FIG. 1 position to cut tubing of smaller diameter, again a single movement of the plunger 13, ie the contraction of the plunger, may result in a master and slave of the interlock system. Form a uniform inward adjustment of the cutting station through the lever.

As mentioned above, one of the individual cutting stations 3 is well shown in FIG. 2. Such a cutting station comprises means for cutting the tube as well as means for driving the tube through the apparatus. This concept is similar to that disclosed in the patents of the two earlier Luck, although the actual shape of the cutter station 3 is new to the present invention.

More particularly, the cutting station 3 comprises a first disc-shaped member 15 having a tread 17 on its outer surface. The second disc-shaped member 19 is disposed at a downstream position with respect to the first disc-shaped member. The outer surface of the disk 19 is provided with a threaded tread portion 21 which partially wraps around the disk. This threaded tread portion 21 is crossed by a rib portion 23 that supports the actual tube cutter 25.

As best shown in FIG. 2, the rib portion 23 is straight rather than having the threaded shape of the tread portion 21. Thus, the ribs lie at 90 ° with respect to the axis of tubing passing through the device and the cuts formed by the cutter 25 are formed in the same direction.

The disc members 15 and 19 are mounted on a conventional rotary support 29. The disk 15 is fixed while the disk 19 is running in the longitudinal direction of the support. As such, the disk 15 and the special tread 17 on this fixed disk are coupled in the trough of the profiled pipe to press the pipe through which the rotation of the disk passes through the device because of the pitch of the tread.

At the same time, the tread portion 21 on the disk 19 is also coupled to the trough of the pipe. However, because of the movable features of the disk, this disk will slide in the downstream direction at the support 29 when the disk is rotated by a tread that engages the pipe.

The disk 19 will rotate to a position where the balance rib 23 and the cutter 25 supported by the rib can move into the trough. As a result of the disk moving with the pipe, the cutter performs the desired right angle cut without any resistance to pipe movement through the device.

When the rib 25 is removed from the trough with the rotation of the disk 19 to complete the pipe cut in this particular area, the disk 19 is adjacent downstream position adjacent disk to perform a new cutting operation of the next trough present in the pipe. Will be returned to (15). This occurs as a result of two things. First, a spring 31 is provided at the downstream end of the disk 19 and this spring is trapped in place by the end stop 31 of the support 29. This end stop holds the entire assembly together.

Secondly, the pitch of the tread portion 21 of the disk 19 is reversed towards the disk 19 when the disk is engaged in the next trough of the pipe after the cut has been made and under the influence of the spring 31 against the disk 19. Causes itself to tread. This action is similar to that described in US Pat. No. 4,218,164.

As also described in both US Pat. Nos. 4,180,357 and 4,218,164, all cutting stations 3 can be rotated simultaneously by a single drive belt for all cutting stations. Such drive belts are wrapped in opposite directions around adjacent rotatable supports of the cutting station to drive adjacent stations in opposite directions in which the tube rotation is prevented. Additional means, such as soft tube grips, are also provided to keep the tube against rotation while the tube is cut.

FIG. 3 shows a modified tube cutting device, denoted 21 in its entirety. This device comprises a plurality of rotating tube cutting stations 23 at circumferentially spaced locations around the central tube passage 24 through the device.

In particular cases the tube cutter 23 is not adjustable radially by the pivotal linkage system but moves in and out relative to the passage 24 by sliding radially directed. In particular, each cutter 23 is rotatably supported by an installation or bar 27 supported by the frame 25. The bar 27 slides the frame in and out relative to the radial adjustment of the tube cutter.

In the embodiment shown in FIG. 3, the operation of the slide system is controlled by the electrical controller 29. Such a controller supplies an impulse by means of sensing means of the surface of the tubing that feeds information to the controller for operation.

For example, by causing the controller to pull the tube cutter away from the cutting position, the detector picks up the access of a large diameter tube area, such as a coupling, to allow the coupling section to pass through the device. Similar sensors are used to operate the described mechanical control system.

Again, with the apparatus of FIG. 3, as with the apparatus of FIG. 1, all cutters can be adjusted simultaneously and uniformly with each other.

According to another aspect of the invention, it may only be necessary for a given cutter to move to the cutting position and retraction or holding of another cutter away from the cutting position may be required. For example, it may be necessary to cut the bottom portion of the tube. This may be achieved using the cutting device 21 at a position where the control can move the cutter at the top of the device radially outward from the cutter position. The cutter at the bottom of the device does not move.

Also for this situation, a means is provided to prevent pipe rotation caused by the imbalance of the cutting area. This means is in the form of a tube grip 3 and the tube grip comprises a housing 33 and a soft tip plunger 35, the soft tip plunger moving radially inward with respect to the tube to hold the tube against rotation.

While various preferred embodiments of the invention have been described in detail, it is recognized by those skilled in the art that modifications can be made without departing from the scope of the appended claims or the spirit of the invention.

Claims (12)

A tube cutting device for forming a plurality of cuts through which a tubing passes and spaced apart around the tubing, A plurality of rotatable members disposed at different circumferential positions around the tube passageway through the device, The respective rotating member is provided with a tube cutter directed toward the tube passageway and spaced from the tube passage with the rotation of the respective member and the rotatable member radially adjusts the tube passage for accommodating the change in diameter in the tubing. Tube cutting device available. The tube cutting device according to claim 1, comprising control means for simultaneous uniform radial adjustment of said plurality of rotatable members. 3. The tube cutting device according to claim 2, wherein said control means makes simultaneous uniform radial adjustment of all said rotatable members. A tube cutting device for forming a circumferentially spaced cut in a trough of a profiled tubing that passes through a tube passageway and passes along the tube passageway. A plurality of rotatable screw members in circumferentially spaced positions around the tube passage, the screw members including tube drive means and tube cutting means and having a radial direction of the tube passage to accommodate a change in diameter of the tubing; Adjustable tube cutting device. 5. A tube cutting device according to claim 4, comprising control means for simultaneous uniform radial adjustment of said plurality of screw members. 5. The tube cutting device according to claim 4, wherein said control means makes simultaneous uniform movement of all said screw members. 6. The system of claim 5 wherein the control means comprises a mechanical linkage system comprising a main lever and a plurality of slave levers pivotally connected to each other, the screw members being pivotally coordinated with each other through a single adjustment of the main lever. And a tube cutting device supported by the slave lever. 8. A tube cutting device according to claim 7, wherein the main lever is actuated by a reciprocating plunger. 6. The tube cutting device according to claim 5, wherein the screw member is supported by a slide support which slides in the radial direction of the tube passage through the operation of the control means. 6. A tube cutting device according to claim 5, wherein said control means comprises an electrical controller. 5. The tube cutting device according to claim 4, wherein the screw member is adjustable to accommodate cutting of tubing of different sizes. 5. A tube cutting device according to claim 4, wherein the screw member is adjustable radially over a significant distance such that the tube coupling section is passed through the device without being cut.